fix(android auto): tapping a song (e.g. in Favoriten) did nothing — re-attach stream URI

Android Auto strips a MediaItem's URI (localConfiguration) when a browse-tree item
crosses the process boundary, so onAddMediaItems received the tapped song without a
playable URI and the else branch passed it through unchanged → no playback. Rebuild
the item with the stream URI resolved from its mediaId.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

android/app/src/main/kotlin/com/novasonic/app/player/MusicService.kt

@@ -385,7 +385,13 @@ class MusicService : MediaLibraryService() {
                                 val pl = repo.getPlaylist(item.mediaId.removePrefix(ITEM_PREFIX_PL))
                                 pl.entry.map { song -> song.toMediaItem(repo) }
                             }
-                            else -> listOf(item)
+                            // A tapped song (e.g. in Favoriten): Android Auto strips the URI
+                            // (localConfiguration) when the browse item crosses the process boundary,
+                            // so it comes back unplayable → nothing happens. Re-attach the stream URI.
+                            else -> {
+                                val uri = repo.streamUrl(item.mediaId)?.let { android.net.Uri.parse(it) }
+                                listOf(item.buildUpon().setUri(uri).build())
+                            }
                         }
                     }
                     settable.set(resolved.toMutableList())